[479449] Raise conflict for addition to single-valued containment ref

If there is no value in a single-valued containment reference and a new
value is set on both sides, it cannot be merged commutatively. However,
EMF Compare did not raise a conflict so far. With this change, a
conflict is raised on such changes. A test case is included.

Note that I didn't put the predicate
ConflictDetectionTest.setOfReference() in EMFComparePredicates in this
change to allow for merging this change without breaking the API. I move
it into EMFComparePredicates in a subsequent change.

Bug: 479449
Change-Id: Ic7d2ea91ca87b0fb47ac0b77db7a87eb78cce5ca
Signed-off-by: Philip Langer <planger@eclipsesource.com>

5 files changed, 113 insertions, 2 deletions

diff --git a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/ConflictDetectionTest.java b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/ConflictDetectionTest.java
index b445f01ef..ceee2605d 100644
--- a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/ConflictDetectionTest.java
+++ b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/ConflictDetectionTest.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012, 2014 Obeo.
+ * Copyright (c) 2012, 2015 Obeo and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  * 
  * Contributors:
  *     Obeo - initial API and implementation
+ *     Philip Langer - bug 479449
  *******************************************************************************/
 package org.eclipse.emf.compare.tests.conflict;
 
@@ -20,6 +21,9 @@ import static org.eclipse.emf.compare.utils.EMFComparePredicates.fromSide;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.moved;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.movedInAttribute;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.movedInReference;
+import static org.eclipse.emf.compare.utils.EMFComparePredicates.ofKind;
+import static org.eclipse.emf.compare.utils.EMFComparePredicates.onEObject;
+import static org.eclipse.emf.compare.utils.EMFComparePredicates.referenceValueMatch;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.removed;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.removedFromAttribute;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.removedFromReference;
@@ -39,6 +43,7 @@ import org.eclipse.emf.compare.Comparison;
 import org.eclipse.emf.compare.Conflict;
 import org.eclipse.emf.compare.ConflictKind;
 import org.eclipse.emf.compare.Diff;
+import org.eclipse.emf.compare.DifferenceKind;
 import org.eclipse.emf.compare.DifferenceSource;
 import org.eclipse.emf.compare.EMFCompare;
 import org.eclipse.emf.compare.scope.DefaultComparisonScope;
@@ -49,6 +54,35 @@ import org.junit.Test;
 
 @SuppressWarnings("nls")
 public class ConflictDetectionTest {
+
+	/**
+	 * This predicate can be used to check whether a given Diff represents the setting of a value in a
+	 * single-valued reference going by {@code referenceName} on an EObject which name matches
+	 * {@code qualifiedName}.
+	 * <p>
+	 * Note that in order for this to work, we expect the EObjects to have a "name" feature returning a String
+	 * for us to compare it with the given qualified name.
+	 * </p>
+	 * <p>
+	 * TODO this is only here to allow us to avoid changing API; should be moved to EMFComparePredicates
+	 * </p>
+	 * 
+	 * @param qualifiedName
+	 *            Qualified name of the EObject which we expect to present a ReferenceChange.
+	 * @param referenceName
+	 *            Name of the multi-valued reference on which we expect a change.
+	 * @param addedQualifiedName
+	 *            Qualified name of the EObject which we expect to have been added to this reference.
+	 * @return The created predicate.
+	 */
+	@SuppressWarnings("unchecked")
+	private static Predicate<? super Diff> setOfReference(final String qualifiedName,
+			final String referenceName, final String addedQualifiedName) {
+		// This is only meant for multi-valued references
+		return and(ofKind(DifferenceKind.ADD), onEObject(qualifiedName), referenceValueMatch(referenceName,
+				addedQualifiedName, false));
+	}
+
 	private ConflictInputData input = new ConflictInputData();
 
 	@Test
@@ -533,6 +567,45 @@ public class ConflictDetectionTest {
 	}
 
 	@Test
+	public void testB3UseCaseForContainmentReference() throws IOException {
+		final Resource left = input.getB3ContainmentReferenceLeft();
+		final Resource origin = input.getB3ContainmentReferenceOrigin();
+		final Resource right = input.getB3ContainmentReferenceRight();
+
+		final IComparisonScope scope = new DefaultComparisonScope(left, right, origin);
+		final Comparison comparison = EMFCompare.builder().build().compare(scope);
+
+		final List<Diff> differences = comparison.getDifferences();
+		final List<Conflict> conflicts = comparison.getConflicts();
+
+		// We should have no less and no more than 2 differences, composing a single conflict
+		assertEquals(2, differences.size());
+		assertEquals(1, conflicts.size());
+
+		final Predicate<? super Diff> leftDiffDescription = setOfReference("root.conflictHolder",
+				"singleValueContainment", "root.conflictHolder.newleft");
+		final Predicate<? super Diff> rightDiffDescription = setOfReference("root.conflictHolder",
+				"singleValueContainment", "root.conflictHolder.newright");
+
+		final Diff leftDiff = Iterators.find(differences.iterator(), and(fromSide(DifferenceSource.LEFT),
+				leftDiffDescription));
+		final Diff rightDiff = Iterators.find(differences.iterator(), and(fromSide(DifferenceSource.RIGHT),
+				rightDiffDescription));
+
+		assertNotNull(leftDiff);
+		assertNotNull(rightDiff);
+
+		// We know there's only one conflict
+		final Conflict conflict = conflicts.get(0);
+
+		final List<Diff> conflictDiff = conflict.getDifferences();
+		assertEquals(2, conflictDiff.size());
+		assertTrue(conflictDiff.contains(leftDiff));
+		assertTrue(conflictDiff.contains(rightDiff));
+		assertSame(ConflictKind.REAL, conflict.getKind());
+	}
+
+	@Test
 	public void testB4UseCaseForAttribute() throws IOException {
 		final Resource left = input.getB4AttributeLeft();
 		final Resource origin = input.getB4AttributeOrigin();
diff --git a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/ConflictInputData.java b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/ConflictInputData.java
index 52cacbc41..2fb05d6f4 100644
--- a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/ConflictInputData.java
+++ b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/ConflictInputData.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012, 2013 Obeo.
+ * Copyright (c) 2012, 2015 Obeo and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -7,6 +7,7 @@
  * 
  * Contributors:
  *     Obeo - initial API and implementation
+ *     Philip Langer - bug 479449
  *******************************************************************************/
 package org.eclipse.emf.compare.tests.conflict.data;
 
@@ -166,6 +167,18 @@ public class ConflictInputData extends AbstractInputData {
 		return loadFromClassLoader("b3/conflict_b3_reference_right.nodes");
 	}
 
+	public Resource getB3ContainmentReferenceLeft() throws IOException {
+		return loadFromClassLoader("b3/conflict_b3_containment_reference_left.nodes");
+	}
+
+	public Resource getB3ContainmentReferenceOrigin() throws IOException {
+		return loadFromClassLoader("b3/conflict_b3_containment_reference_origin.nodes");
+	}
+
+	public Resource getB3ContainmentReferenceRight() throws IOException {
+		return loadFromClassLoader("b3/conflict_b3_containment_reference_right.nodes");
+	}
+
 	public Resource getB4AttributeLeft() throws IOException {
 		return loadFromClassLoader("b4/conflict_b4_attribute_left.nodes");
 	}
diff --git a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_left.nodes b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_left.nodes
new file mode 100644
index 000000000..05a6433bd
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_left.nodes
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>

+<nodes:Node xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:nodes="http://www.eclipse.org/emf/compare/tests/nodes" xmi:id="_ioJ60JQ1EeGUu8zWDEISZA" name="root">

+  <containmentRef1 xmi:id="_ioJ60ZQ1EeGUu8zWDEISZA" name="origin"/>

+  <containmentRef1 xmi:id="_ioJ60pQ1EeGUu8zWDEISZA" name="left"/>

+  <containmentRef1 xmi:id="_0EQv4JQ2EeGUu8zWDEISZA" name="right"/>

+  <containmentRef1 xsi:type="nodes:NodeSingleValueContainment" xmi:id="_ioJ605Q1EeGUu8zWDEISZA" name="conflictHolder">

+    <singleValueContainment xmi:id="_newleft" name="newleft"/>

+  </containmentRef1>

+</nodes:Node>

diff --git a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_origin.nodes b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_origin.nodes
new file mode 100644
index 000000000..3c6bfaf73
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_origin.nodes
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>

+<nodes:Node xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:nodes="http://www.eclipse.org/emf/compare/tests/nodes" xmi:id="_ioJ60JQ1EeGUu8zWDEISZA" name="root">

+  <containmentRef1 xmi:id="_ioJ60ZQ1EeGUu8zWDEISZA" name="origin"/>

+  <containmentRef1 xmi:id="_ioJ60pQ1EeGUu8zWDEISZA" name="left"/>

+  <containmentRef1 xmi:id="_0EQv4JQ2EeGUu8zWDEISZA" name="right"/>

+  <containmentRef1 xsi:type="nodes:NodeSingleValueContainment" xmi:id="_ioJ605Q1EeGUu8zWDEISZA" name="conflictHolder"/>

+</nodes:Node>

diff --git a/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_right.nodes b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_right.nodes
new file mode 100644
index 000000000..84fce0fbc
--- /dev/null
+++ b/plugins/org.eclipse.emf.compare.tests/src/org/eclipse/emf/compare/tests/conflict/data/b3/conflict_b3_containment_reference_right.nodes
@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>

+<nodes:Node xmi:version="2.0" xmlns:xmi="http://www.omg.org/XMI" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:nodes="http://www.eclipse.org/emf/compare/tests/nodes" xmi:id="_ioJ60JQ1EeGUu8zWDEISZA" name="root">

+  <containmentRef1 xmi:id="_ioJ60ZQ1EeGUu8zWDEISZA" name="origin"/>

+  <containmentRef1 xmi:id="_ioJ60pQ1EeGUu8zWDEISZA" name="left"/>

+  <containmentRef1 xmi:id="_0EQv4JQ2EeGUu8zWDEISZA" name="right"/>

+  <containmentRef1 xsi:type="nodes:NodeSingleValueContainment" xmi:id="_ioJ605Q1EeGUu8zWDEISZA" name="conflictHolder">

+    <singleValueContainment xmi:id="_newright" name="newright"/>

+  </containmentRef1>

+</nodes:Node>